On 4/7/20 1:36 PM, Joseph Christopher Sible wrote: > When a process is blocking in io_uring_enter, and a signal stops it for > any reason, it returns -EINTR to userspace. Two comments about this: > > 1. https://github.com/axboe/liburing/blob/master/man/io_uring_enter.2 > doesn't mention EINTR as a possible error that it can return. I'll add it to the man page. > 2. When there's no signal handler, and a signal stopped the syscall for > some other reason (e.g., SIGSTOP, SIGTSTP, or any signal when the > process is being traced), other syscalls (e.g., read) will be > restarted transparently, but this one will return to userspace > with -EINTR just as if there were a signal handler. > > Point 1 seems like a no-brainer. I'm not sure if point 2 is possible > to fix, though, especially since some other syscalls (e.g., epoll_wait) > have the same problem as this one. Lots of system calls return -EINTR if interrupted by a signal, don't think there's anything worth fixing there. For the wait part, the application may want to handle the signal before we can wait again. We can't go to sleep with a pending signal. -- Jens Axboe
